Washer

ABSTRACT

A washer has a structure to prevent overheating of a heater. The washer includes a tub to contain wash water, a rotating drum provided in the tub, a heater to heat water in the tub, and a circulation unit to supply water in the tub to the rotating drum. A circulation hole is formed at a height same as or greater than a mounting height of the heater to allow water to flow into the circulation unit. This prevents the height of water from becoming less than the mounting height of the heater even when the circulation unit is in operation, thereby preventing overheating of the heater.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of Korean Patent Application No. 2007-0030060, filed on Mar. 27, 2007 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field

Embodiments relate to a washer, and more particularly, to a washer including a circulation unit to circulate wash water and a heater to heat wash water.

2. Description of the Related Art

Washers are generally classified into top-load washers and front-load washers. The top-load washer includes a pulsator and a wash tub rotating about a rotating shaft that is provided in a case along a vertical direction. The front-load washer includes a wash tub rotating about a rotating shaft that is provided in a case along a substantially horizontal direction.

An example of the front-load washer is described in Korean Patent Application Publication No. 10-2007-0023146.

The washer of this publication includes a case that is opened at one side, a tub that is mounted in the case to contain wash water, a drum that is rotatably mounted about a rotating shaft provided in the tub along a horizontal direction, and an electric heater that is mounted at a lower portion of inside of the tub to heat wash water contained in the tub.

A drainage tube and a drainage pump are provided under the tub. One end of the drainage tube is connected to one end of a circulation flow path so that the drainage tube and the circulation flow path communicate with each other to circulate wash water contained in the tub. The other end of the circulation flow path extends upward to be connected to an upper portion of the tub so that the circulation flow path and the tub communicate with each other. A circulation pump is provided in the circulation flow path to circulate wash water.

Upon completion of water supply, this washer detects the level of water in the tub and activates the heater to heat the water if the detected water level is higher than a heater safety level.

In the washer described in the publication, the drainage tube is connected to a lower portion of the tub and the circulation flow path is connected to one end of the drainage tube so that the circulation flow path and the drainage tube communicate with each other as described above. Thus, when the circulation pump is in operation, water in the tub is supplied to the rotating drum through the circulation flow path. The height of water in the tub may become less than the mounting height of the electric heater since a connection between the tub and the drainage tube is provided at a height less than the mounting height of the electric heater mounted in the tub. In this case, the electric heater comes into contact with the air, resulting in overheating to cause failure of the heater and fire.

Especially, when the electric heater operates even though the water level is lower than the heater safety level due to failure of the water level sensor or the like, the water level is further lowered due to the operation of the circulation pump as compared to when the circulation pump operates at a normal water level, since water in the tub still flows into the circulation pump due to the operation of the circulation pump. This increases the risk of failure of the electric heater and fire due to overheating of the electric heater.

SUMMARY

An aspect of embodiments provides a washer having a structure to prevent overheating of a heater.

In accordance with an aspect of an embodiment, there is provided a washer for washing laundry including a tub; a rotating drum rotatably mounted in the tub, wherein the rotating drum receives laundry; a heater to heat water in the tub, wherein the heater is mounted to the tub; and a circulation unit to supply water in the tub to the rotating drum, wherein a circulation hole is formed in the tub at a height greater than a mounting height of the heater and the circulation hole allows water to flow into the circulation unit.

The height of the circulation hole may be less than a height of a lower surface of the rotating drum.

The circulation hole may be formed in a front portion or a cylinder portion of the tub.

The circulation unit may include a circulation pump provided on an external surface of the tub and a circulation tube provided between the circulation pump and the rotating drum.

The washer may further include a drainage unit to drain water in the tub, wherein a drainage hole is formed at a lower portion of the tub to allow water to flow out to the drainage unit.

The washer may further include a single drive pump to drive the circulation unit and the drainage unit; and a flow path switching valve to change a flow path at an outlet side of the drive pump.

The tub may include a heater seat that is recessed downwardly to mount the heater on the heater seat, wherein the drainage hole is formed in the heater seat.

In accordance with an aspect of an embodiment, there is provided a washer for washing laundry including a tub; a rotating drum rotatably mounted in the tub, wherein the rotating drum receives laundry; a heater to heat water in the tub, wherein the heater is mounted to the tub; a circulation unit to supply water in the tub to the rotating drum; a drainage unit to drain water in the tub, wherein the tub has a drainage hole to allow water to flow to the drainage unit and a circulation hole to allow water to flow to the circulation unit, the circulation hole being formed at a height that is a predetermined distance greater than a mounting height of the heater.

The tub may include a heater seat that is recessed downwardly to mount the heater on the heater seat, wherein the drainage hole is formed in the heater seat.

The height of the circulation hole may be less than a height of a lower surface of the rotating drum.

The height of a bottom of the circulation hole may be substantially the same as the height of a top of the heater.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects, features, and advantages will become apparent and more readily appreciated from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a sectional view of a washer according to an exemplary embodiment;

FIGS. 2A and 2B are partial sectional views illustrating how a circulation pump of the washer according to an exemplary embodiment operates;

FIG. 3 is a control block diagram of the washer according to an exemplary embodiment;

FIG. 4 is a sectional view of a washer having a tub and a circulation unit combined with each other according to a modification o an exemplary embodiment; and

FIG. 5 is a sectional view of a washer according to another exemplary embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. Exemplary embodiments are described below by referring to the figures.

FIG. 1 is a sectional view of a washer according to an exemplary embodiment.

As shown in FIG. 1, the washer according to an exemplary embodiment includes a cabinet 10, a tub 20, a rotating drum 30, a water supply unit 40, a drainage unit 50, and a circulation unit 60. The cabinet 10 defines the exterior of the washer. The tub 20 is provided inside the cabinet 10 to contain wash water. The rotating drum 30 is rotatably mounted in the tub 20. The water supply unit 40 supplies detergent and wash water into the tub 20. The drainage unit 50 drains wash water in the tub 20 out of the cabinet 10. The circulation unit 60 supplies wash water in the tub 20 into the rotating drum 30.

The cabinet 10 has a box-like shape. An opening 11, through which laundry, such as clothes, is inserted into and removed from the rotating drum 30, is defined in the front surface of the cabinet 10. A door 12 is hinged to the cabinet 10 at one portion of the opening 11 to open and close the opening 11.

The tub 20 in the cabinet 10 includes a front portion 21 having an opening 21 a at a central portion of the front portion 21, a rear portion 22 in which a drive motor 13 described below is mounted, and a cylinder portion 23 through which the front portion 21 and the rear portion 22 are connected to each other.

A diaphragm 24 and a guide member 25 are mounted on the front portion 21. The diaphragm 24 is provided between the opening 11 of the cabinet 10 and the opening 21 a of the tub 20 to prevent leakage of wash water. The guide member 25 is provided inside the diaphragm 24 to guide laundry such as clothes for easy insertion and removal.

The diaphragm 24 also has a supply hole 24 a through which wash water received from the water supply unit 40 is supplied into the tub 20.

A heater 26 is provided at a lower portion of inside of the cylinder portion 23 to heat wash water to more effectively wash laundry such as clothes. The tub 20 includes a heater seat 23 a to which the heater 26 is fixed. The heater seat 23 a is recessed downwardly with a sloping wall to prevent the heater 26 from contacting the tub 20 or the rotating drum 30 and to allow the heater 26 to effectively heat wash water.

The heater 26 includes a heating portion 26 a to generate heat to warm wash water when power is applied. The heating portion 26 a is designed to have a plurality of bends to maximize heating efficiency in a given space.

The drive motor 13, which is a drive source to rotate a rotating shaft 14 coupled to the rotating drum 30, is mounted at a rear portion of the tub 20. The drive motor 13 includes a stator 13 a fixed to the rear of the tub 20, a rotor 13 b that is rotatably mounted about the stator 13 a, and a rotating plate 13 c through which the rotator 13 b and the rotating shaft 14 are connected to each other.

The rotating drum 30 mounted in the tub 20 includes a front portion 31 having an opening 31 a at a central portion of the front portion 31, a rear portion 32 coupled to the drive motor 13, and a cylinder portion 33 through which the front portion 31 and the rear portion 32 are connected to each other.

A plurality of lifters 33 a are mounted on the inner surface of the cylinder portion 33 of the rotating drum 30 to lift and drop wash water in the rotating drum 30 when the rotating drum 30 rotates. A number of through-holes 33 b are formed along the surface of the cylinder portion 33 to allow inflow and outflow of wash water. When the rotating drum 30 rotates at a high speed, the centrifugal force causes wash water to flow out of the rotating drum 30 through the through-holes 33 b.

The water supply unit 40 is provided above the tub 20 inside the cabinet 10. The water supply unit 40 includes a water supply valve 41, a detergent supply unit 42, a first water supply tube 43, and a second water supply tube 44. The water supply valve 41 controls supply of wash water flowing into the cabinet 10. The detergent supply unit 42 stores detergent. The first water supply tube 43 connects the water supply valve 41 and the detergent supply unit 42 to each other. The second water supply tube 44 supplies wash water, in which detergent is dissolved through the detergent supply unit 42, into the tub 20. Accordingly, wash water is supplied into the tub 20 after passing through the detergent supply unit 42 in which detergent stored in it is dissolved in the wash water.

The drainage unit 50 is provided under the tub 20 to drain wash water in the tub 20 out of the cabinet 10. The drainage unit 50 includes a first drainage tube 51, a drainage pump 52, and a second drainage tube 53. The first drainage tube 51 is connected to a drainage hole 23 b formed in the heater seat 23 a under the tub 20 so as to guide water in the tub 20 out of the cabinet 10. The first drainage tube 51 is connected to the inlet side of the drainage pump 52. The second drainage tube 53 is connected to the outlet side of the drainage pump 52. Of course, the drainage pump 52 may be replaced with a drainage valve in a drainage structure that permits natural drainage.

Since the drainage hole 23 b is formed in a lower surface of the heater seat 23 a, it can prevent wash water from remaining in the tub 20 when the wash water drains, thereby avoiding freezing of water remaining in the tub 20 during a cold winter and also preventing offensive smells, bacterial pollution, and the like due to the stagnant water remaining for a long time.

In order to reduce wash water consumption and to improve wash performance, the washer according to an exemplary embodiment further includes the circulation unit 60 to supply wash water in the tub 20 into the rotating drum 30. The circulation unit 60 includes a first circulation tube 61, a circulation pump 62, a second circulation tube 63, and a spray nozzle 64. The first circulation tube 61 is connected to a circulation hole 21 b formed in the front portion 21 of the tub 20. The circulation pump 62 is connected to the first circulation tube 61 to pump wash water in the tub 20 into the rotating drum 30. The second circulation tube 63 extends from the circulation pump 62 toward the opening 31 a of the rotating drum 30. The spray nozzle 64 is mounted at an outlet of the second circulation tube 63.

The circulation hole 21 b can be formed under the front portion 21 of the tub 20 at a height which can be a predetermined distance greater than the mounting height of the heater 26. Preferably, the circulation hole 21 b is formed at a height that is same as or greater than the mounting height of the heater 26 and less than that of the lower surface 34 of the rotating drum 30 and the bottom (or lower side) of the circulation hole 21 b can be formed substantially at the same height as that of the top of the heater 26.

FIGS. 2A and 2B are partial sectional views illustrating how the circulation pump of the washer according to an exemplary embodiment operates.

When the circulation pump 62 operates while the heater 26 is on, as shown in FIG. 2A, water in the tub 20 flows into the rotating drum 30 through the circulation unit 60 and the level (or height) of water supplied in the tub 20 is lowered due to the operation of the circulation pump 62. If the height of water in the tub 20 becomes less than the mounting height h1 of the heater 26, the heating portion 26 a of the heater 26 comes into contact with the air, resulting in overheating to cause failure of the heater 26 and fire.

According to an exemplary embodiment, the circulation hole 21 b is provided at a height h2 same as or greater than the mounting height h1 of the heater 26 as described above. This allows the heating portion 26 a of the heater 26 to be always submerged in water regardless of the operation of the circulation pump 62 as shown in FIG. 2B, thereby essentially preventing the heater 26 from being in contact with the air.

In addition, the bottom of the circulation hole 21 b can be formed substantially at the same height as that of the top of the heater 26, thereby allowing smooth circulation of wash water through the circulation unit 60.

The circulation pump 62 is provided on the front portion 21 of the tub 20 to provide a pumping force to cause wash water in the tub 20 to flow into the rotating drum 30. Mounting the circulation pump 62 on the front portion 21 minimizes the lengths of the first and second circulation tubes 61 and 63. This reduces residual water in the first and second circulation tubes 61 and 63, thereby reducing wash water consumption.

One portion of the second circulation tube 63 is connected to the circulation pump 62 and the other portion passes through the diaphragm 24 of the tub 20. The spray nozzle 64 is provided on the end of the other portion of the second circulation tube 63 to spray wash water into the rotating drum 30. The spray nozzle 64 is provided at a portion of the guide member 25 adjacent to the opening 31 a of the rotating drum 30.

Preferably, the second circulation tube 63 passes through an upper portion of the circular diaphragm 24 and is connected to the spray nozzle 64 provided at the side of the opening 31 a of the rotating drum 30 so as to uniformly spray wash water to laundry such as clothes.

The drainage hole 23 b and the circulation hole 21 b are separately provided in the washer according to an exemplary embodiment. That is, the drainage hole 23 b is formed in the heater seat 23 a in the lower surface of the tub 20 and the circulation hole 21 b can be formed at a position that is a predetermined distance higher than the mounting position of the heater 26. This prevents the water height of the tub 20 from being less than the height of the heating portion 26 a of the heater 26 when the circulation pump 62 operates and also allows water to flow out through the drainage hole 23 b during drainage, thereby preventing water from remaining in the tub 20.

FIG. 3 is a control block diagram of the washer according to an exemplary embodiment. The washer includes a signal input unit 71, a water level sensor 72, a temperature sensor 73, a controller 74, and a drive unit 75 in addition to the components shown in FIG. 1.

The signal input unit 71 inputs operation information selected by the user, such as wash cycle, wash temperature, spin-dry RPM, and the addition of rinse, to the controller 74. The water level sensor 72 senses the level (or height) of water supplied in the tub 20. The temperature sensor 73 senses temperature of water supplied in the tub 20.

The controller 74 is a microcomputer that controls the washer according to the operation information input from the signal input unit 71. The controller 74 turns on/off the circulation pump 62 and the heater 26 based on the water level sensed by the water level sensor 72. The controller 74 also compares the temperature sensed by the temperature sensor 73 with a preset temperature and turns on/off the heater 26 based on the comparison.

The drive unit 75 drives the drive motor 13, the heater 26, the water supply valve 41, the water pump 52, and the circulation pump 62 according to a drive control signal from the controller 74.

The following is a description of how the water according to an exemplary embodiment operates.

First, if the user selects operation information such as wash cycle, spin-dry RPM, and wash temperature according to the wash cycle according to the type of laundry (such as clothes) after inserting the laundry (such as clothes) into the rotating drum 30 and puts detergent into the detergent supply unit 42, then the selected operation information is input to the controller 74 through the signal input unit 71.

Thereafter, if the washer is activated, the water supply valve 41 is opened to supply wash water into the tub 20. Since the wash water is supplied into the tub 20 after passing through the detergent supply unit 42, detergent in the detergent supply unit 42 is dissolved in the wash water to be supplied into the tub 20. If the water level sensor 72 detects that an appropriate amount of wash water has been supplied to the tub 20, then the controller 74 closes the water supply valve 41 to terminate water supply.

Here, the heater 26 provided under the tub 20 is submerged in the water supplied to the tub 20. After water supply is terminated, the heater 26 is activated to heat the supplied wash water at the preset wash temperature. After or while the wash water is heated at the preset temperature, the circulation pump 62 is activated to supply the heated wash water in the tub 20 into the rotating drum 30 through the first and second circulation tubes 61 and 63. Here, the wash water is sprayed into the rotating drum 30 through the spray nozzle 64, thereby uniformly wetting the laundry (such as clothes) while the wash cycle is performed.

The tub 20 included in the washer according to an exemplary embodiment is constructed such that the circulation hole 21 b can be formed at a height between the top of the heating portion 26 a of the heater 26 and the lower surface 34 of the cylinder portion 33 of the rotating drum 30, so that the height of water in the tub 20 does not become less than that of the heating portion 26 a of the heater 26 even when the circulation pump 62 is in operation. This prevents overheating of the heater 26 that might otherwise occur since the heater 26 is in direct contact with the air.

If the water level is inaccurately sensed due to failure of the water level sensor 72 or the like, the heater 26 may be kept on even though the water level is low. In this case, even though the circulation pump 62 is in operation, only water above the heating portion 26 a of the heater 26 flows into the circulation hole 21 b, thereby preventing overheating of the heater 26.

In addition, there is an advantage in that hot water risen by convection can be supplied to the rotating drum 30 since the circulation hole 21 b is located above the conventional circulation hole.

There is another advantage in that, in a drain or dry cycle after the wash cycle is terminated, the drainage pump 52 is activated to cause water in the tub 20 to drain through the drainage hole 23 b, thereby preventing residual water from remaining in the tub 20.

The following is a description of a washer according to a modification of an exemplary embodiment.

FIG. 4 is a sectional view of a washer having a tub and a circulation unit combined with each other according to the modification of an exemplary embodiment.

A circulation hole 21 c is formed in a cylinder portion 23 of a tub 20 of the washer according to the modification of an exemplary embodiment. The circulation hole 21 c is formed at a height that is greater than the mounting height of a heater 26 and less than the lower surface of a cylinder portion 33 of a rotating drum 30 as in the above exemplary embodiment,

A circulation unit 80 communicating with the circulation hole 21 c includes first and second circulation tubes 81 and 83, a circulation pump 82, and a circulation nozzle 84. Water flowing out of the circulation hole 21 c is supplied to the rotating drum 30 through the first and second circulation tubes 81 and 83. The circulation pump 82 is provided between the first and second circulation tubes 81 and 83 to provide a pumping force. The circulation nozzle 84 is provided on the end of the second circulation tube 83.

The washer configured in this manner also has the same advantages as the above exemplary embodiment.

The following is a description of a washer according to another exemplary embodiment.

FIG. 5 is a sectional view of a washer according to another exemplary embodiment.

Components similar to those of exemplary embodiment of FIG. 1 are denoted by like reference numerals and a description of those components are omitted here.

The washer according to an exemplary embodiment includes a drainage unit 100, a circulation unit 110, a drive pump 103, and a flow path switching valve 112. The drainage unit 100 drains water in the tub 20. The circulation unit 110 supplies water in the tub 20 into the rotating drum 30. The drive pump 103 drives the drainage unit 100 and the circulation unit 110. The flow path switching valve 112 is provided at a portion of the drive pump 103 to switch the flow path.

The drainage unit 100 includes a first drainage tube 101, a drainage valve 102, and a second drainage tube 104. The first drainage tube 101 is connected to the drainage hole 23 b formed in the heater seat 23 a under the tub 20 to guide water in the tub 20 out of the cabinet 10. The drainage valve 102 is provided in the middle of the first drainage tube 101 to open and close the first drainage tube 101. The second drainage tube 104 is connected to the outlet side of the drive pump 103.

The circulation unit 110 includes a first circulation tube 111, a second circulation tube 113, and a spray nozzle 114. One portion of the first circulation tube 111 is connected to the circulation hole 21 b provided in the front portion 21 of the tub 20 and the other portion is connected to the drive pump 103. One portion of the second circulation tube 113 is connected to the flow path switching valve 112 and the other portion extends toward the opening 31 a of the rotating drum 30. The spray nozzle 114 is mounted on the outlet of the second circulation tube 113.

The inlet side of the drive pump 103 is connected to the first circulation tube 111 and the first drainage tube 101 so that the single drive pump can be driven to perform the drain or circulation cycle.

The flow path switching valve 112 is provided at the outlet side of the drive pump 103 to switch the flow path to allow water pumped by the drive pump 103 to flow into one of the second circulation tube 113 and the second drainage tube 104. The flow path switching valve 112 includes a general three-way electric valve.

In the case where the circulation unit 110 operates to supply heated water in the tub 20 into the rotating drum 30, the drive pump 103 is activated to circulate water from the tub 20 to the rotating drum 30, with the drainage valve 102 closed and the flow path switching valve 112 operated to allow water introduced to the first circulation tube 111 to flow into the second circulation tube 113.

In the case where the drainage unit 100 operates to drain water in the tub 20, the drive pump 103 is activated to drain water in the tub 20 out of the cabinet 10 through the circulation hole 21 b and the drainage hole 23 b, with the drainage valve 102 opened and the flow path switching valve 112 operated to allow water to flow into the second drainage tube 104.

As is apparent from the above description, a washer according to an exemplary embodiment has a variety of advantages. For example, a circulation hole is provided, separately from a drainage hole provided under a tub, at a height greater than the mounting height of a heater. This prevents the height of water in the tub from becoming less than the mounting height of the heater even when a circulation unit is in operation, thereby preventing overheating of the heater. This also allows water in the tub to drain through the drainage hole in a drainage or dry cycle, thereby preventing residual water from remaining in the tub.

In addition, in the case where the heater and the circulation pump are kept on even though the water level is low since the water level is inaccurately sensed due to failure of a water level sensor or the like, only water above the heating portion of the heater flows into the circulation hole, thereby preventing overheating of the heater.

Moreover, hot water risen by convection can be supplied to a rotating drum since the circulation hole is located above the conventional circulation hole.

Although a few exemplary embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these exemplary embodiments, the scope of which is defined in the claims and their equivalents. 

1. A washer for washing laundry comprising: a tub; a rotating drum rotatably mounted in the tub, wherein the rotating drum receives laundry; a heater to heat water in the tub, wherein the heater is mounted to the tub; and a circulation unit to supply water in the tub to the rotating drum, wherein a circulation hole is formed in the tub at a height same as or greater than a mounting height of the heater and the circulation holes allows water to flow into the circulation unit.
 2. The washer according to claim 1, wherein the height of the circulation hole is less than a height of a lower surface of the rotating drum.
 3. The washer according to claim 1, wherein the circulation hole is formed in a front portion of the tub.
 4. The washer according to claim 1, wherein the circulation unit includes a circulation pump provided on an external surface of the tub and a circulation tube provided between the circulation pump and the rotating drum.
 5. The washer according to claim 1, further comprising: a drainage unit to drain water in the tub, wherein a drainage hole is formed at a lower portion of the tub to allow water to flow out to the drainage unit.
 6. The washer according to claim 5, further comprising: a single drive pump to drive the circulation unit and the drainage unit; and a flow path switching valve which is positioned at an outlet side of the single drive pump, wherein the flow path switching valve changes a flow path of water.
 7. The washer according to claim 5, wherein the tub includes a heater seat that is recessed downwardly to mount the heater on the heater seat.
 8. A washer for washing laundry comprising: a tub; a rotating drum rotatably mounted in the tub, wherein the rotating drum receives laundry; a heater to heat water in the tub, wherein the heater is mounted to the tub; a circulation unit to supply water in the tub to the rotating drum; a drainage unit to drain water in the tub, wherein the tub has a drainage hole to allow water to flow to the drainage unit and a circulation hole to allow water to flow to the circulation unit, the circulation hole being formed at a height that is a predetermined distance greater than a mounting height of the heater.
 9. The washer according to claim 8, wherein the tub includes a heater seat that is recessed downwardly to mount the heater on the heater seat.
 10. The washer according to claim 8, wherein the height of the circulation hole is less than a height of a lower surface of the rotating drum.
 11. The washer according to claim 8, wherein a height of a bottom of the circulation hole is substantially the same as a height of a top of the heater.
 12. The washer according to claim 1, wherein the circulation hole is formed in a cylinder portion of the tub.
 13. The washer according to claim 1, wherein a height of a bottom of the circulation hole is substantially the same as a height of a top of the heater.
 14. The washer according to claim 7, wherein the drainage hole is formed in the heater seat.
 15. The washer according to claim 9, wherein the drainage hole is formed in the heater seat. 